Rock-drilling machine.



No. 896,518. v PATENTED AUG. 18, 1908. 1

J. B. DAMAS & JQ FRANCIS. ROCK DRILLING MACHINE.

AlPLIGATION FILED SEPT. 20, 1907.

l k 1 w:

\ I/ N u i 4 2 4 w:- In

W/ T/Vfijfj //v Vf/V TEA/6 John 5. flame- 101e,, flaw-.5 rt v 15 ;f4/7% JOHN B. DAMAS AND JOSEPH FRANOIS, OF SONORA, CALIFORNIA.

Boon-DRILLING MACHINE.

Specification of Letters Patent;

Patented Aug. 18, 1908;

' Application filed September 20, 1907 Serial No. 393,797.

To all: whom it may concern:

Be it known that we, JOHN B. DAMAS and JosEPH FRANCIS, both citizens of the United valve after its work in the cylinder is com- 40 any suitable manner.

States, residing at Sonora, in thecounty of Tuolumne and State of California, have invented new and useful Im rovements in ing is a specification.

' Our invention relates to improvements in rock drilling machines, and consists in a means by which exhaust air from the reciprocating engine is utilized to blow the cuttings away from the cutting bits or tool as the work progresses. 5

It also comprises details of construction which will, be-more fully explained by reference to the accompanying drawings, in Which Figure 1 is'a longitudinal section of a drill showing our invention. Fig. 2 is a similar view in another position. Fig. 3 is a view showing end of drill.

We have here shown our invention applied to a drilling engine which was patented to John B. Dama's, September 8, 1903, #738,416, but it will be understood that it may be applied to any similarly impelled engine.

As herein shown, A is a cylinder, and B a double headed piston adapted to reciprocate therein when impelled by any medium under pressure. Air is usually employed in this class ofengines.

3 is a slide valve movable upon a valve seat, havingl the customary chambers connecting wit ports 4 leading to the ends of the cylinder, and to a central exhaust chamher 5, through which the air from the cylinder is discharged by the movements of the pleted. The valve 3 may be reciprocated in unison with the movements .of the piston, in

In the present illustration it is actuated by a T-shaped lever 6 so fulcrumed as to be actuated by the recipr'ocations of .the "piston, and having one arm made to engage the valve. The pistonrod 7 is hollow, as shown at 8, and connects The reciprocations of the engine piston are communicated to the drill, which continually cu ts away the rock, and to prevent these cuttings from clogging and impeding the drill in its work, the air blast admitte into the-piston and drill shank, acts to blow the cuttings out of the hole in the rock, and thus leave the face against which the drill acts,

substantially clean and free.

During the reciprocations of the piston within the cylinder, the T-shaped lever has its ends alternately lifted by the larger ends of the piston, and the opposite end which .engages the valve 3, causes said valve to slide upon its seat so as to open communication alternately .between the pressure chamber and the cylinder ends, and also between the op site ends of the cylinder and the exhaust c amber 5. This chamber comshank as previously described.

Having thus described our invention, what we claim and desire to secure by Letters Patent is- 1. In an elastic fluid impelled engine, a cylinder, '.a piston having heads at opposite ends fitting said cylinder, and an intermediate connection of smaller diameter, a slide valve with ports ada ted to connect with o posite ends of the cy inder, and alternately admit and exhaust an impelling fluid, an exhaust receiving chamber communicating with the cylinder between the piston heads, a hollow piston rod fixed to the piston, openings through the iston connectin the exhaust chamber with the interior of tile piston rod, and a hollow drill shank in 0 en coinminication with the interior of tie piston ro 2. In an elastic fluid in; elled engine, a cylinder, a piston reciprocab e therein, a hollow piston-rod and hollow drill with a connecting chuck, a slide valve, and means by which it is reciprocated in unison with the piston, With inlet and exhaust ports conset our hands in presence of two subscribing trolled thereby, end' an exhaust receiving witnesses.

chamber said 'giston having passages con- JOHN B. DAMAS.

necting the ex aust chamber with the in- JOSEPH'FRANCIS. 5 terior of the piston-rod and through the drill Witnesses; r

to the cutting edge. R; G. C-UnNow,

Intestimony whel eofwe have hereunto JO NCAREY. 

